Environment Notes 10

Risk Assessment Categories of Species

The International Union for Conservation of Nature (IUCN), founded in 1948, is a global authority on the status of the natural world and the measures needed to safeguard it. Its most renowned work is the IUCN Red List of Threatened Species, established in 1964, which is a critical indicator of the health of the world’s biodiversity. The classification of a species into a risk category is not arbitrary but is based on a rigorous set of quantitative criteria. These criteria were developed to make the system objective and globally applicable.

The five core quantitative criteria used for assessment are:

1. Population Size Reduction: This measures the rate of decline over the last 10 years or three generations, whichever is longer. A severe decline rate places a species in a higher threat category. For instance, a decline of over 80-90% would classify a species as Critically Endangered.
2. Geographic Range: This considers the extent of occurrence (the geographical spread) and the area of occupancy (the actual area inhabited by the species). A very restricted range makes a species more vulnerable to localized threats like habitat destruction or disease outbreaks.
3. Small Population Size and Decline: This criterion looks at species with a small number of mature individuals and a continuing decline. For example, a population with fewer than 250 mature individuals and an ongoing decline would be considered Endangered.
4. Very Small or Restricted Population: This applies to species with an extremely small population (e.g., fewer than 50 mature individuals for Critically Endangered) or those restricted to a single location, making them susceptible to a single catastrophic event.
5. Quantitative Analysis (Population Viability Analysis - PVA): This involves using statistical models to predict the probability of extinction in the wild over a specific timeframe. For example, a species with a 50% probability of extinction within 10 years or 3 generations would be classified as Critically Endangered.

Categories of Risk

A. Extinct (EX): A taxon is Extinct when there is no reasonable doubt that the last individual has died. This conclusion is reached after exhaustive surveys in its known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual.

• Historical Context: The period from the 17th century onwards, often associated with the Age of Exploration and colonialism, saw a dramatic increase in extinctions due to direct human actions and the introduction of invasive species.
• Examples:
  • Dodo (Raphus cucullatus): This flightless bird, endemic to Mauritius, became extinct by 1681. Its extinction is a classic case study, attributed not only to hunting by Dutch sailors but also to the introduction of invasive species like pigs, dogs, and macaques, which preyed on Dodo eggs and outcompeted them for food. The ecologist Alfred W. Crosby in his work “Ecological Imperialism” (1986) detailed how such biological invasions devastated native island ecosystems.
  • Pink-headed Duck (Rhodonessa caryophyllacea): An enigmatic diving duck, it was last definitively sighted in 1949. It inhabited the dense, swampy grasslands and forests of the Gangetic plains and parts of Myanmar. Its extinction is primarily attributed to large-scale habitat loss due to the conversion of wetlands for agriculture, compounded by hunting pressure.
  • Indian Cheetah (Acinonyx jubatus venaticus): The Asiatic Cheetah, a subspecies distinct from its African cousin, was declared extinct in India in 1952. Its decline was a long process, starting with habitat loss (loss of grasslands) and a decline in its prey base. The final blow was delivered by sport hunting during the British Raj and by Indian royalty. The last confirmed sighting in the wild was in 1947 when Maharaja Ramanuj Pratap Singh Deo of Surguja shot the last three individuals in present-day Chhattisgarh.
  • Barbary Lion (Panthera leo leo): This lion subspecies, native to the Atlas Mountains of North Africa, was famed for its dark, extensive mane. It was driven to extinction in the wild by the mid-20th century (last shot in Morocco in 1942) due to widespread hunting for sport and bounties. However, genetic studies on lions in captivity, particularly those descended from the collection of the King of Morocco, suggest that some individuals may carry Barbary lion ancestry, making it technically “Extinct in the Wild” for some researchers, though its pure lineage is debated.
  • Hawaiian Crow or ʻAlalā (Corvus hawaiiensis): This species became Extinct in the Wild in 2002. Its decline was caused by a combination of habitat loss, diseases like avian malaria (transmitted by introduced mosquitoes), and predation by introduced species. It now survives only in captive breeding facilities in the United States, with ongoing efforts for reintroduction.

B. Extinct in the Wild (EW): A taxon is Extinct in the Wild when it is known only to survive in cultivation, in captivity, or as a naturalized population well outside the past range. Surveys in its native range have failed to locate any individuals.

C. Threatened Species: This is a collective term for three specific categories: Critically Endangered, Endangered, and Vulnerable.

• (1) Critically Endangered (CR): Faces an extremely high risk of extinction in the wild.

  • Criteria: Population decline of ≥90% over 10 years; population size of fewer than 50 mature individuals; or a quantitative analysis showing a probability of extinction in the wild of at least 50% within 10 years or three generations.
  • Examples:
    • Malabar Civet (Viverra civettina): Endemic to the Western Ghats, this is one of the world’s most threatened and elusive mammals. It is gravely threatened by the destruction and fragmentation of its lowland forest and wetland habitat.
    • Sumatran Rhinoceros (Dicerorhinus sumatrensis): The smallest and hairiest of the living rhinoceroses, it was once found across Northeast India, Southeast Asia, and the islands of Sumatra and Borneo. It is now extinct in India and Malaysia, with only a few dozen individuals remaining in fragmented populations in Sumatra and Kalimantan (Indonesian Borneo), threatened by poaching and habitat loss.
    • Great Indian Bustard (Ardeotis nigriceps): A large terrestrial bird native to India and Pakistan. Its population has plummeted due to habitat loss (conversion of grasslands to agriculture), hunting, and collisions with power lines. The majority of the remaining population (around 150 individuals) is found in the Desert National Park, Rajasthan.
    • Gharial (Gavialis gangeticus): A unique, fish-eating crocodile with a long, thin snout. Once widespread across the Indian subcontinent’s river systems, its population is now largely confined to the National Chambal Sanctuary, with smaller populations in the Ghaghara and Gandak rivers. Threats include dam construction, river pollution, and illegal sand mining, which destroys their nesting sites.

• (2) Endangered (EN): Faces a very high risk of extinction in the wild.

  • Criteria: Population decline of ≥70% over 10 years; population size of fewer than 250 mature individuals; or a quantitative analysis showing a probability of extinction in the wild of at least 20% within 20 years or five generations.
  • Examples:
    • Himalayan Musk Deer (Moschus leucogaster): Inhabits the high alpine forests of the Himalayas. It lacks antlers; instead, males possess tusk-like canines and a musk gland highly prized in the perfume industry. This demand has led to severe poaching, making it endangered.
    • Indian Wild Dog (Dhole) (Cuon alpinus): A highly social canid found in Central, South, and Southeast Asia. In India, they inhabit the highlands of Central India and the Western and Eastern Ghats. They are threatened by habitat loss, depletion of prey base, persecution by humans, and diseases transmitted from domestic dogs.
    • Lion-tailed Macaque (Macaca silenus): An arboreal primate endemic to the rainforests of the Western Ghats. Its survival is intrinsically linked to contiguous tracts of evergreen forest. The primary threat is habitat fragmentation due to agriculture, plantations, and construction of reservoirs, which isolates populations and reduces their genetic diversity.

• (3) Vulnerable (VU): Faces a high risk of extinction in the wild.

  • Criteria: Population decline of ≥50% over 10 years; population size of fewer than 1,000 mature individuals; or a probability of extinction of at least 10% within 100 years.
  • Examples:
    • One-horned Rhinoceros (Rhinoceros unicornis): A conservation success story, its status was improved from Endangered to Vulnerable due to stringent protection and anti-poaching efforts in India (especially Kaziranga and Manas National Parks in Assam) and Nepal. However, poaching for its horn remains a persistent threat.
    • Indian Bison (Gaur) (Bos gaurus): The largest extant bovine, found in South and Southeast Asia. While still widespread, its populations are threatened by habitat loss, hunting, and diseases like foot-and-mouth disease transmitted from domestic cattle.
    • Four-horned Antelope (Chousingha) (Tetracerus quadricornis): Unique for being the only bovid with four horns (in males), it is found in the forests of India and Nepal. It is threatened by the loss of its dry forest and scrubland habitat to agriculture.
    • Swamp Deer (Barasingha) (Rucervus duvaucelii): Known for its 12-tined antlers. There are three subspecies adapted to hard ground, swamps, and mangroves. The hard-ground subspecies was brought back from the brink of extinction in Kanha National Park through dedicated conservation efforts.
    • Dugong (Sea Cow) (Dugong dugon): A marine mammal that feeds exclusively on seagrass. It is found in shallow coastal waters from East Africa to Australia. In India, populations exist in the Gulf of Mannar, Gulf of Kutch, Palk Bay, and the Andaman and Nicobar Islands. Threats include seagrass bed destruction, water pollution, and entanglement in fishing nets.

D. Near Threatened (NT): A taxon that is close to qualifying for, or is likely to qualify for, a threatened category in the near future.

E. Least Concern (LC): A taxon that is widespread and abundant and does not qualify for any of the threatened categories.

F. Data Deficient (DD): Inadequate information is available to make a direct or indirect assessment of its risk of extinction.

G. Not Evaluated (NE): A taxon that has not yet been evaluated against the criteria.

IUCN Categories of Protected Areas

The IUCN defines a protected area as “A clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values.” The IUCN has developed a system of six management categories based on the primary management objective.

• (1a) Strict Nature Reserve:

  • Objective: To protect biodiversity and also geological/geomorphological features, where human visitation, use and impacts are strictly controlled and limited to ensure protection of the conservation values.
  • Characteristics: These areas are managed mainly for scientific research and environmental monitoring. They serve as essential reference areas for understanding the natural state of ecosystems. Human access is highly restricted.
  • Indian Context: No protected area in India perfectly fits this category due to demographic pressures. However, the ‘Core Zones’ of some Biosphere Reserves and National Parks (like the core of Nanda Devi Biosphere Reserve) are managed with principles close to this category, aiming for minimal human interference.

• (1b) Wilderness Area:

  • Objective: To protect large, unmodified or slightly modified areas, retaining their natural character and influence, without permanent or significant human habitation, which are protected and managed so as to preserve their natural condition.
  • Characteristics: These are larger than Category 1a reserves and may allow for traditional, non-destructive human activities by indigenous communities. The focus is on preserving the ‘wilderness’ quality. Modern infrastructure is absent.
  • Indian Context: Large, remote, and sparsely populated National Parks like Hemis National Park in Ladakh or parts of the Gulf of Mannar Marine National Park could be considered to have attributes of a Wilderness Area, where vast tracts remain largely untouched by modern development.

• (2) National Park:

  • Objective: To protect natural biodiversity along with its underlying ecological structure and supporting environmental processes, and to promote education and recreation.
  • Characteristics: These are large natural areas set aside to protect large-scale ecological processes, along with the complement of species and ecosystems characteristic of the area. They have a dual mandate of conservation and controlled human use (tourism, education). Human occupation and resource exploitation are generally prohibited, though traditional rights might be accommodated in some buffer zones.
  • Indian Context: This category directly corresponds to the National Parks established under India’s Wildlife (Protection) Act, 1972. Examples like Jim Corbett, Kanha, and Bandipur National Parks are managed to conserve flagship species (tiger, elephant) and their ecosystems while facilitating regulated tourism.

• (3) Natural Monument or Feature:

  • Objective: To protect a specific natural monument, which can be a landform, sea mount, submarine cavern, geological feature such as a cave or even a living feature such as an ancient grove.
  • Characteristics: These are generally smaller protected areas focused on conserving specific outstanding natural features and their associated biodiversity and habitats. They often have high visitor and recreational value.
  • Indian Context: While India does not formally use this category, sites like Lonar Crater in Maharashtra (a crater formed by a meteor impact) or the Siwalik Fossil Park in Himachal Pradesh would fit the description of a Natural Monument. Similarly, sacred groves, protected by communities, often preserve ancient trees and unique biodiversity, reflecting the spirit of this category.

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Prelims Pointers

• IUCN: International Union for Conservation of Nature, headquartered in Gland, Switzerland.
• IUCN Red List: Established in 1964, it is the world’s most comprehensive inventory of the global conservation status of biological species.
• Threatened Categories: A grouping of Critically Endangered (CR), Endangered (EN), and Vulnerable (VU).
• Critically Endangered Criteria: Population decline of ≥90% in 10 years OR population size < 50 mature individuals.
• Endangered Criteria: Population decline of ≥70% in 10 years OR population size < 250 mature individuals.
• Vulnerable Criteria: Population decline of ≥50% in 10 years OR population size < 1000 mature individuals.
• Extinct Species: Dodo (Mauritius), Pink-headed Duck (India), Indian Cheetah (declared extinct in India in 1952).
• Critically Endangered Species in India: Malabar Civet (Western Ghats), Sumatran Rhino (now extinct in India), Great Indian Bustard (Rajasthan), Gharial (Chambal River).
• Endangered Species in India: Lion-tailed Macaque (Western Ghats), Himalayan Musk Deer, Indian Wild Dog (Dhole).
• Vulnerable Species in India: One-horned Rhino (Assam), Gaur (Indian Bison), Dugong (Sea Cow), Swamp Deer (Barasingha).
• Species Specifics:
  • Lion-tailed Macaque is endemic to the Western Ghats.
  • Great Indian Bustard is primarily found in the Desert National Park, Rajasthan.
  • Gharial is a fish-eating crocodile found mainly in the Chambal river basin.
  • Dugong is a herbivorous marine mammal that feeds on seagrass.
• IUCN Protected Area Categories:
  • Category Ia: Strict Nature Reserve (Scientific research).
  • Category Ib: Wilderness Area (Large, unmodified, traditional use allowed).
  • Category II: National Park (Ecosystem conservation and recreation).
  • Category III: Natural Monument (Specific natural features).
• National Parks Mentioned: Hemis (largest in India), Desert NP, Kaziranga, Manas, Gir, Kanha.

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Mains Insights

1. Interplay of Human Activity and Biodiversity Loss (GS-III: Environment):

• Cause-Effect Analysis: The examples provided illustrate a clear causal link between human activities and species extinction. The extinction of the Dodo was driven by direct hunting and indirect ecological disruption through invasive species. The Indian Cheetah’s extinction was a direct result of habitat conversion for agriculture and sport hunting. The ongoing threat to the Lion-tailed Macaque is due to habitat fragmentation for developmental projects.
• Historiographical Viewpoint: This pattern supports the concept of the ‘Anthropocene’, a proposed geological epoch where human activity is the dominant influence on climate and the environment. Scholars like Paul Crutzen argue that this epoch began with the Industrial Revolution, marking an acceleration in human-induced extinctions and ecological changes.
• Policy Implication: Conservation policies must move beyond species-centric approaches to address the root drivers of biodiversity loss, including unsustainable land use, infrastructure development, and consumption patterns.

2. Debates in Conservation Strategies: ‘Fortress’ vs. ‘Inclusive’ Conservation (GS-I: Social Issues & GS-III: Environment):

• Fortress Conservation: The IUCN Category Ia (Strict Nature Reserve) represents the “fortress” or “fences and fines” approach, which seeks to protect nature by excluding human presence. This model has been criticized by social scientists like Mark Dowie in “Conservation Refugees” (2009) for often leading to the displacement and disenfranchisement of indigenous and local communities who have historically coexisted with nature.
• Inclusive Conservation: Categories Ib (Wilderness Area) and II (National Park) in theory, and the Man and Biosphere (MAB) Programme in practice, represent a more inclusive approach. This model recognizes the rights and traditional knowledge of local communities, seeking their participation in conservation. The Forest Rights Act, 2006, in India is a legislative step in this direction, aiming to balance conservation goals with the livelihood rights of forest-dwelling communities.
• The Way Forward: The challenge lies in finding a pragmatic balance. While strict protection is necessary for critically endangered habitats, long-term conservation success depends on ensuring that local communities are stakeholders and beneficiaries, not adversaries, of conservation efforts.

3. Efficacy of National and International Conservation Frameworks (GS-II: Governance & GS-III: Environment):

• International Frameworks: The IUCN Red List provides the scientific basis and moral imperative for global conservation action. It guides policy for international conventions like CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) and the CBD (Convention on Biological Diversity).
• National Legislation: In India, the Wildlife (Protection) Act, 1972, provides the legal backbone for establishing protected areas (National Parks, Sanctuaries). The success of ‘Project Tiger’ (1973) and the recovery of the One-horned Rhino demonstrate the effectiveness of targeted, well-funded conservation programs under this act.
• Contemporary Challenges: Despite strong laws, implementation faces challenges from poaching networks, human-wildlife conflict, and pressure to dilute environmental regulations for economic development. The recent Cheetah reintroduction project, while ambitious, highlights the complexities and debates surrounding ecological restoration, including questions of genetic suitability and habitat carrying capacity.

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